Damage caused by Tibraca limbativentris nymphs and adults in different stages of the rice crop

The piercing-sucking insects present in different crops cause physiological and morphological changes during vegetative development and flowering. However, more knowledge is needed about whether plant mechanisms are affected by stink bug injury, especially that imposed by nymphs and male or female adults. Furthermore, the feeding time of piercing-sucking insects can significantly alter crop damage. This study was conducted to determine the damage caused by different life stages (nymphs and adults) and by different sexes of Tibraca limbativentris in two rice plant phenological stages. The development and yield were evaluated following the infestation of nymphs and adults of different sexes in the vegetative and reproductive stages of rice plants. In addition, the development, yield, and gas exchange of rice plants infested under different nymph densities in the vegetative and reproductive stages were evaluated. We did not find any consistent relationship between the number of nymphs and rice yield. T. limbativentris nymphs did not cause losses to grain yield on rice in this study (in both experiments). However, the nymphs caused a significant increase in the number of stalks exhibiting dead heart symptoms, showing results similar to the adult insects. Nymph feeding affected photosynthetic processes in rice leaves only when infestations happened at the vegetative stage. Stomatal conductance was also affected when infestations occurred at the reproductive stage. Further studies are critical to understand the mechanisms underlying the injury and to evaluate the potential damage of nymphs under field conditions. The impact caused by the combination of nymphs and adults in the field must be evaluated.